The primary objective is to assess the pharmacokinetics of nelfinavir when given in combination with ZDV and 3TC and to assess the safety and tolerance of the triple combination therapy in HIV-1 infected women during pregnancy and post partum and to assess the pharmacokinetics of nelfinavir when given in combination with ZDV and 3TC and to assess the safety and tolerance of the triple combination therapy in HIV-1 exposed infants.